The invention discloses an XML configuration-based detection method for authorization difference between information systems. User information of all the information systems is exported as an EXCEL file to be uploaded, a WEB server obtains and parses the uploaded file, and a two-dimensional array set of a preliminary analysis result is obtained through the user information and role corresponding relation information; then, in combination with two-dimensional array set of the preliminary analysis result and role inheritance relations, a two-dimensional array set of a final detection result is obtained, the two-dimensional array set records authorization difference of the same user in different information systems, and automatic detection of the authorization difference between different information systems is completed. According to the method, the condition of the authorization difference between the information systems is automatically found out through a computer, and therefore the problems that a manual authority sorting method wastes time and labor, and is large in workload and prone to error are solved; automatic traversal detection is achieved through an XML configuration file, and therefore detecting accuracy is improved; a manager can adapt to changes of authorization information by modifying the configuration file, and maintenance is facilitated.